Chimera

Term (chimaera = hybrid being) in medicine and biology for an organism that is made up of genetically different cells or tissues and yet represents a uniform individual. In Greek mythology, this actually means "goat"; Homer (born 850 BC) describes the Chimaira in the Iliad as a fire-breathing hybrid creature that is shaped like a lion at the front, a goat in the centre and a snake or dragon at the back. The best-known example of such hybrid creatures is the Egyptian sphinx at the pyramids of Giza; a lion with a human head.

In plants, a chimera can also be created artificially by human intervention, for example by grafting by combining two different plants (lower part = rootstock and upper part = scion). In viticulture, all grafted vines are therefore to be understood as mesoclinal chimeras. Chimeras arise naturally through mutation, in which cells are derived from at least two genetically different zygotic lines (diploid cells). This frequently occurring phenomenon is known from ornamental plants, where sectoral chimeras with multi-coloured petals or elongated striped, white-green or purple-green-white leaves occur. In contrast, periclinal ch imeras are plants whose outer epidermal tissue differs from the genotype of the inner cell lines due to mutations, whereby the mutations occur in both cell lines independently of each other and at different gene loci.